Detection of biomechanical changes after corneal cross-linking using Ocular Response Analyzer software.

Area of Science:

• Ophthalmology
• Biomechanical Engineering
• Corneal Science

Background:

• Keratoconus is a progressive corneal ectasia characterized by structural weakness.
• Corneal cross-linking (CXL) aims to stiffen the cornea and halt disease progression.
• Assessing biomechanical changes post-CXL is crucial for evaluating treatment efficacy.

Purpose of the Study:

• To investigate biomechanical changes in keratoconic corneas after corneal cross-linking (CXL).
• To evaluate the utility of new Ocular Response Analyzer (ORA) software parameters in detecting these changes.
• To compare post-CXL biomechanical properties with healthy controls.

Main Methods:

• Utilized ORA software (version 2.04) to obtain 37 new biomechanical parameters from 50 keratoconic eyes before and 1 year after CXL.
• Compared measurements with 96 age-matched healthy control eyes.
• Analyzed changes in corneal hysteresis (CH) and corneal resistance factor (CRF).

Main Results:

• Corneal hysteresis (CH) and corneal resistance factor (CRF) showed no significant change after CXL.
• The area under peak 2 (p2area) significantly increased by 35% (P=.001) 1 year post-CXL.
• A significant negative correlation was found between p2area and the difference in CH-CRF values (r=-0.29, P=.001).

Conclusions:

• The area under peak 2 (p2area) is a more sensitive indicator of biomechanical changes post-CXL than CH or CRF alone.
• Corneal biomechanics are altered after CXL in keratoconus patients.
• Post-CXL corneas exhibit biomechanical properties distinct from healthy corneas.